Evolving trends in hepatitis A epidemiology: Shifting patterns, emerging risks, and future strategies

Table 5 Outbreaks related to hepatitis A virus infection

Group	Region	Key details	Ref.
Men who have sex with men	Europe, United States, Israel, Chile, Poland, Barcelona	1400 cases in 16 European Union/European Economic Area countries; three HAV strains; linked outbreaks in Israel/Chile; mostly non-immune men who have sex with men engaging in high-risk sexual behaviour, increase risk with concomitant HIV infection	Ndumbi et al[89], Enkirch et al[90], Raczyńska et al[91], Dabrowska et al[92]
Patient who inject drugs	California, Michigan, Kentucky, Utah, London, Ontario	Increased HAV cases among persons who inject drugs or homelessness due to low vaccination coverage, syndemic involving concomitant HIV, HCV, HAV and group A streptococcal infection	Foster et al[93], Turner[94]
Foodborne	Europe, Italy, Sweden, Austria, United States, Michigan	Large European Union and Italy outbreak from frozen berries; Sweden, Austria, Michigan linked to imported strawberries; outbreaks from contaminated food or infected food handlers	Fallucca et al[95], Authority[96], Hutin et al[97], Greig and Ravel[98]
Travelers/migration	France, United States of America (United States)	Travel-related cases account for approximately 30%-46% of HAV cases in United States/Europe; 254 cases of hepatitis A in international travellers, with most cases occurring in unvaccinated individuals	Migueres et al[99], Balogun et al[100]
Homelessness	San Diego (United States), San Francisco (United States)	People experiencing homelessness had 3.3 × higher odds of infection, higher hospitalization and death rates; prevalence increased with years of homelessness, injection drug use, and foreign-born status	Peak et al[101], Hennessey et al[102]
Community transmission	Brazil, Germany	Person-to-person transmission common in enclosed spaces; 34.3% of household contacts infected; outbreak among Ukrainian war refugees and volunteer caregiver	Lima et al[103], Krumbholz et al[104]
HIV positive patients	Iran, Warsaw, Poland	97.7% HAV seroprevelance; outbreaks in HIV positive men who have sex with men	Dabrowska et al[92], Omidifar et al[105]
Chronic liver disease (HBV and HCV)	Italy, Argentenia	HAV superinfection causes severe disease, fulminant hepatitis; higher fatality in coinfected patients; HAV outbreaks among men who have sex with men show high rates of HIV, syphilis and HBV co-infection	Vento et al[106], Marciano et al[107]
Metabolic dysfunction associated steatotic liver disease	United States	Increase odds of liver fibrosis	Vassilopoulos et al[108]

HAV: Hepatitis A virus; HBV: Hepatitis B virus; HCV: Hepatitis C virus; HIV: Human immunodeficiency virus.